LMH6645 - 2.7V, 650µA, 55MHz, Rail-to-Rail Input and Output Amplifiers with Shutdown Option

The LMH6645 (single) and LMH6646 (dual), rail-to-rail input and output voltage feedback amplifiers, offer high speed (55 MHz), and low voltage operation (2.7 V) in addition to micro-power shutdown capability (LMH6647, single).

Input common mode voltage range exceeds either supply by 0.3 V, enhancing ease of use in multitude of applications where previously only inferior devices could be used. Output voltage range extends to within 20 mV of either supply rails, allowing wide dynamic range especially in low voltage applications. Even with low supply current of 650 µA/amplifier, output current capability is kept at a respectable ±20 mA for driving heavier loads. Important device parameters such as BW, Slew Rate and output current are kept relatively independent of the operating supply voltage by a combination of process enhancements and design architecture.

In portable applications, the LMH6647 provides shutdown capability while keeping the turn-off current to less than 50 µA. Both turn-on and turn-off characteristics are well behaved with minimal output fluctuations during transitions. This allows the part to be used in power saving mode, as well as multiplexing applications. Miniature packages (SOT-23, VSSOP-8, and SOIC-8) are further means to ease the adoption of these low power high speed devices in applications where board area is at a premium.

• (V_S = 2.7V, T_A = 25°C, R_L = 1kΩ to V⁺/2, A_V = +1.
  Typical Values Unless Specified.
• −3dB BW 55 MHz
• Supply Voltage Range 2.5 V to 12 V
• Slew Rate 22 V/µs
• Supply Current 650 µA/channel
• Output Short Circuit Current 42 mA
• Linear Output Current ±20 mA
• Input Common Mode Voltage 0.3 V Beyond Rails
• Output Voltage Swing 20 mV from Rails 
• Input Voltage Noise 17 nV/√Hz
• Input Current Noise 0.75 pA/√Hz